Speed Limit

A speed limit is a regulation establishing the maximum speed at which it is permitted to drive a motor vehicle along a given road or section of road. While practical enforcement procedures vary, anyone exceeding the limit by any amount is committing an offence in law.

Current speed limits on roads in the United Kingdom have come about through many years of traffic regulation legislation. The origins go back to the early days of motoring, but perhaps the key legislation that defines our modern day limits is the Road Traffic Act 1934, which introduced the concept of different speed limits for built up and non built up roads, essentially applying a restricted speed limit to roads that were street lit and making non street lit roads de-restricted.

The restricted road speed limit of 30 mph for cars and motorcycles has been with us since the 1934 act. At that time, since few motor vehicles were capable of exceeding the modern 60 mph limit, non lit roads were deemed to be derestricted, thus had no speed limit. The national speed limit was first introduced late in 1965 as an experiment on all previously derestricted roads. Various amendments saw the national speed limit introduced first as a standard 70 mph, then amended several times, most notably due to the 1973 oil crisis, before becoming 60 mph on single-carriageway roads and 70 mph on dual-carriageway roads in the late 1970s.

Vehicle class speed limits also apply on UK roads, these restrict certain classes of vehicle, notably, goods vehicles over 7.5 tonnes, buses, coaches and vehicles towing trailers to different speed limits for three different types of road, single carriageway, dual carriageway and motorway.

It should be noted that non-motorway Special Roads have no specifically defined national speed limit, and the maximum speed limit is always stated in the Statutory Instrument that creates the road. This means that the National Speed Limit sign has no clear meaning, and so non-motorway Special Roads always have their speed limit explicitly signed. It has been debated on SABRE many times as to whether the lower class limits apply to non-motorway Special Roads, usually to no firm conclusion. At the time of writing, there does not appear to be any case law on the subject to offer guidance.

Variable speed limits

On some motorways, called smart motorways, speed limits can be varied to manage traffic flow. This is called variable speed limit or VSL. This is shown using AMI signs above individual lanes or on all lane running schemes, verge mounted MS4 signals.

VSL and lane diversion symbols on a VSL-enabled MS4 on the M1 to prepare for an incident in lane 1 of the ALR scheme.

Sensors and CCTV as well as an advanced MIDAS system can automatically set VSL and it may be used with or without hard shoulder running.
Unlike advisory speed limits which can be set using most variable message signs and so can be used on any motorway, variable speed limits need either AMI or an MS4 capable of showing VSL (on some motorways MS4s are used to show advisory speeds without VSL). The MS4s that can use VSL must be fitted with a camera sign on the cantilever or gantry. This is because variable speed limits have a red circle around them instead of flashing lights-this makes following them a legal requirement.

VSL can also be used on some A roads, but this is mainly on a few selected roads in Scotland and Wales and is very rare, if at all used, on English A roads.

Local speed limits

Local speed limits are introduced where the appropriate national speed limit for a road is deemed inappropriate by the traffic authority responsible. Local speed limits must be signed accordingly at each end and by means of repeater signs at regular intervals along the road that the local speed limit applies.

A local speed limit cannot be made for a road that would otherwise come under the classification of the national speed limit, for example, if a road had a 40 mph local speed limit and was to be reduced to 30 mph, then the appropriate sections of the road traffic act would be used to revoke the local limit and make the road a restricted road. The national speed limit may be deemed inappropriate for a variety of reasons, including geometric road quality, casualty rates, importance of road, community severence, amount of frontage to the road, introduction of street lighting to a high quality road.

Vehicle class speed limits

The maximum speed a motor vehicle can travel on a road is not only defined by the road type, but also the vehicle class;

Speed Limits

Built-up areas *

Single carriage-ways

Dual carriage-ways

Motorways

Type of vehicle

mph (km/h)

mph (km/h)

mph (km/h)

mph (km/h)

Cars and motorcycles

(including car-derived vans up to 2 tonnes maximum laden weight)

30 (48)

60 (96)

70 (112)

70 (112)

Cars towing caravans or trailers

(including car-derived vans and motorcycles)

30 (48)

50 (80)

60 (96)

60 (96)

Buses, coaches, and minibuses

(not exceeding 12 metres in overall length)

30 (48)

50 (80)

60 (96)

70 (112)

Goods vehicles

(not exceeding 7.5 tonnes maximum laden weight)

30 (48)

50 (80)

60 (96)

70 (112) **

Goods vehicles

(exceeding 7.5 tonnes maximum laden weight)

30 (48)

50 (80) ***

60 (96) ***

60 (96)

* The 30 mph limit usually applies to all traffic on all roads with street lighting unless signs show otherwise.
** 60 mph (96 km/h) if articulated or towing a trailer.
*** These limits apply only to England and Wales, in Scotland and Northern Ireland the limit on a dual carriageway for goods vehicles exceeding 7.5 tonnes max laden weight is 50mph (80 km/h) and on a single carriageway 40 mph (64 km/h)

Speed limits can only apply to motor vehicles. Therefore, in a urban area with a 20 mph speed limit, a pedal-powered bicycle exceeding that speed is not committing an offence.

Other speed limits

Although common on private land, speed limits other than those prescribed by the DfT require approval from the Secretary of State. Speed limit signs that are prescribed by the DfT are for 20 mph, 30 mph, 40 mph, 50 mph, 60 mph and the National Speed Limit (white sign with a black diagonal bar). The 20 mph can be indicated by means of a circular sign as a speed limit, or by means of a larger square sign bearing the 20 mph roundel and the word "ZONE" below.

Speed Limit Signage

Speed Limiters

Speed limiters are being fitted to an increasing number of motor vehicles. Since 1 January 2005 all newly registered goods vehicles with a design weight over 3.5 tonnes and buses are required by law to be fitted with a road speed limiter. The requirement for older vehicles came into staged operation through to 1 January 2008.

Exceeding the speed limit

Anyone exceeding a speed limit by as little as one mile per hour is breaking the law. However, in practice, owing to the inaccuracy of speedometers, the Association of Chief Police Officers (ACPO), which provides guidance and recommendation of police procedures, recommends that in normal circumstances no action be taken against a driver not exceeding the limit by more than 10% + 2 mph. Therefore, driving at 34 mph where the speed limit is 30 mph, or 68 mph where the speed limit is 60 mph, will not normally result in a prosecution, though it is still legitimately possible.

Speedometers are required by law to never read less than the vehicle's true speed, and never more than 110% + 4 km/h.

Key legislation

Road Traffic Regulation Act 1984

Current act that details aspects of traffic regulation, including the specific detail of law covering speed limits. The relevant parts for speed limits are covered in "Part IV Speed Limits", specifically sections 81-89. Supersedes the Road Traffic Regulation Act 1967.

Section 17 Gives the Secretary of State for Transport, the Scottish Ministers or members of the Welsh Assembly powers to create traffic restrictions (including speed limits) on special roads.

Section 81 Defines that "it shall not be lawful for a person to drive a motor vehicle on a restricted road at a speed exceeding 30 miles per hour"

Section 82 Defines that a restricted road is where there is provided on it a system of street lighting furnished by means of lamps placed not more than 200 yards apart.

Section 82 also enables a traffic authority to direct if a road shall cease to be a restricted road or shall become a restricted road. Essentially, allowing the traffic authority to make a higher speed limit on a street lit road or to make a road that already has a different speed limit in place to become a restricted road.

Section 83 Defines who may create a speed limit order and that public notice is required.

Section 84 Defines what an order may prohibit, including the speed at which motor vehicles may not exceed and the period that the speed limit will cover. This section also defines that a traffic authority has power to make an order, that public notice shall be given before introducing an order and that Section 84 shall not apply to any part of a special road.

Section 87 Provides an exemption for fire, ambulance and police vehicles in situations (e.g. during an emergency call) where observance would hinder the use of the vehicle for the purpose for which it is being used. The section also covers (in England and Wales only) vehicles being used by "Serious Organised Crime Agency" vehicles and "for training persons to drive vehicles for use for Serious Organised Crime Agency purposes, as it applies in relation to a vehicle being used for police purposes."

Section 88 Covers temporary speed limits, including the what the temporary speed limit is, the period of operation, defines a maximum period of 18 months and

Section 89 Defines that "A person who drives a motor vehicle on a road at a speed exceeding a limit imposed by or under any enactment to which this section applies shall be guilty of an offence."

The Motorways Traffic (Speed Limit) Regulations 1974

This piece of legislation enacted under the 1967 RTRA and currently empowered by Sect. 17 of the RTRA creates the 70 mph national speed limit that applies to all motorways.

Regulation 3 This is the key provision that prohibits the driving of a motor vehicle at a speed greater than 70 mph on a motorway.

The 70 miles per hour, 60 miles per hour and 50 miles per hour (Temporary Speed Limit) Order 1977

This order creates the national speed limit on all purpose roads. This order was enacted under the 1967 RTRA.

Regulation 2 This provision prohibits the driving of a motor vehicle at a speed greater than 70 mph on a dual carriageway. It also provides some lower limits for a few specified roads.
Regulation 3 This provision prohibits the driving of a motor vehicle at a speed greater than 60 mph on a single carriagway. It also provides some lower limits for a few specified roads.

The 70 miles per hour, 60 miles per hour and 50 miles per hour (Temporary Speed Limit) (Continuation) Order 1978

This order has the effect of making the preceding temporary order permanent. This order was enacted under the 1967 RTRA and is currently empowered by Sect. 84 of RTRA

This statutory instrument amends the speed limit in England and Wales for HGVs from 40 to 50 mph on single carriageways and from 50 to 60 mph on dual carriageways not subject to a lower limit.

Historical Legislation

Highways Act 1835

Brought highways under the direction of Parish Surveyor who would be responsible for the maintenance and improvement of the local highways. Defines the nearside rule of riding on the left hand side of the road, numerous offences and defines the widths of roads;

Cartways to be Twenty Feet wide (Approximately 6.1m)

Horseways Eight Feet

Footways Three Feet

Locomotive Act of 1861

Introduced the concept of a different speed limit for urban and rural roads and defined a fine mechanism.

"It shall not be lawful to drive any Locomotive along any Turnpike Road or public Highway at a greater Speed than Ten Miles an Hour, or through any City, Town, or Village at a greater Speed than Five Miles an Hour; and any Person acting contrary hereto shall for every such Offence, on summary Conviction thereof before Two Justices, if he be not the Owner of such Locomotive, forfeit any Sum not exceeding Five Pounds, and if he be the Owner thereof, shall forfeit any Sum not exceeding Ten Pounds."

Locomotive Act of 1865

Reduced the speed limits introduced in the 1861 act to 4 mph in the countryside and 2 mph in towns. Also required three crew for each vehicle, a driver, a stoker/passenger and a red flag man walking 60 yards in advance of the motor vehicle.

Highways and Locomotives (Amendment) Act 1878

Amended section three of the 1865 act to reduce the distance the red flag had to be in advance of the motor vehicle and a requirement to stop on sight of a horse.

"section three of the Locomotive Act, 1865, is hereby repealed, so far as relates to England, and in lieu thereof the following paragraph is hereby substituted; namely, “Secondly, one of such persons, while the locomotive is in " motion, shall precede by at least twenty yards the locomotive " on foot, and shall in case of need assist horses, and carriages " drawn by horses, passing the same."

This act also give power for existing rural sanitary authorities to become highway boards and also granted power of county authority to license locomotives, thus removing the requirement for a red flag man.

Locomotives on Highways Act 1896

This act was perhaps the first encouraging sign that motor car ownership had become acceptable. The act removed the rules on speed limits and the use of a red flag for a new class of vehicle called a "light locomotive" which had to weigh less than 3 tons and made the vehicle exempt from the 3 crew rule. The act imposed a new higher 14 mph speed limit on the light locomotive, this however could be reduced to 12 mph by most local government boards.

Locomotives Act 1898

Motor Car Act 1903

Introduction of car registration and the diving license and raised the previous 14 mph speed limit to 20 mph with a provision for introduction of lower speed limit of 10 mph fixed after a local inquiry.

Roads Act 1920

Defined various points over vehicle classification, licensing of drivers, driving offences, the duty to stop after an accident, vehicle weights, requirement for third party insurance, regulation of public service vehicles, introduced traffic commissioners/areas and introduced the following speed limits.

Motor Vehicles (Variation of Speed Limit) Regulations 1961

Motor Vehicles (Variation of Speed Limit) Regulations 1962

The maximum speed limit for goods vehicles without trailers will go up from 30 mph to 40 mph

The general speed limit for goods vehicles with trailers will go up from 20 mph to 30 mph

The general speed limit for light goods vehicles towing light trailers or caravans the limit will go up from 20 mph to 40 mph

The limit for cars towing heavy trailers will go up from 20 mph to 30 mph

The limit for cars towing light trailers or caravans will be raised from 30 mph to 40 mph

The maximum speed for tractors and locomotives, provided that they conform to certain standards of design in regard to brakes, tyres, springs and wings, will be raised from 20 mph to 30 mph and if they are towing trailers of similar standards, from 12 mph to 20 mph

The limit for motor tractors with two or more trailers and locomotives with 318 more than two trailers will be raised from 5 mph to 12 mph

Motor Vehicles (Speed Limit on Motorways) Regulations 1966

Increased the maximum speed for vehicles drawing trailers on motorways from 40 to 50 mph and raised the maximum speed limit for a motor car drawing a glider trailer from 30 mph to 40 mph

The M4 Motorway (Severn Bridge) (Speed Limit) Regulations 1995

A statutory instrument (1995 No. 2168) that enabled a 40 mph speed limit to be introduced when indicated by signs along the length of the Second Severn Crossing. This lower speed limit could be introduced temporally for road works or during periods of high wind.

Other relevant legislation

The Motorways Traffic (England and Wales) Regulations 1982

A statutory instrument (1995 No. 158) that changed the definition of vehicles prohibited to use the right hand (offside) lane of a motorway carriageway which has three or more lanes.

This had the effect of banning "a passenger vehicle which is constructed or adapted to carry more than eight seated passengers in addition to the driver the maximum laden weight of which exceeds 7.5 tonnes" (generally coaches and buses) from using the right hand (offside) lane of motorway with three or more lanes.

The Motorways Traffic (England and Wales)(Amendment) Regulations 2004

A statutory instrument (2004 No. 3258) that changed the definition of vehicles prohibited to use the right hand (offside) lane of a motorway carriageway which has three or more lanes.

This had the effect of banning "a goods vehicle which having a maximum laden weight exceeding 3.5 tonnes but not exceeding 7.5 tonnes" (generally many larger transit/sprinter type vehicles) from using the right hand (offside) lane of motorway with three or more lanes.

Road Safety Act 2006

This legislation includes a provision that (once enacted) will modify Sect. 87 of the RTRA to restrict the exemptions to speed limits for emergency vehicles to drivers that have completed an authorized training course. It also introduces an open ended provision to allow orders issued under the RTRA to prescribe additional exemptions.